1. Field
The following generally relates to networking architectures. More particularly, the following relates to unified networks, and elements thereof, for vehicles, such as aircrafts, artificial satellites, spacecrafts watercrafts and the like. The following further relates to networking architectures and/or unified networks for other (i.e., non-vehicular) applications.
2. Related Art
Aircraft avionics architectures have evolved over the past fifty years or so in response to developments in electrical, electronic and optical communication and communication media technologies. First generation avionic architectures were distributed analog systems. In these systems, signals were generated by sensors on the aircraft. These signals were passed as modulated electrical signals in analog format to user interfaces that presented the processed signals in an intelligible manner.
Second generation avionics architectures replaced the analog signals with digitally formatted signals, with an associated increase in signal robustness, immunity to interference, and reliability. The organizational principle, however, was unchanged, representing distributed digital systems. That is, individual digital signals were routed on electrical wires to individual user interface elements.
As the electronics technologies continued to improve, multiplexed databuses were introduced, allowing many independent digital signals to utilize a common wiring infrastructure. This was achieved mostly by electronically multiplexing the digital signals onto databus wiring, using protocols defined to ensure orderly utilization of the shared medium—the databus wiring.
Third generation avionic architectures are referred to as federated architectures to signify all elements of a specific aircraft system, such as the navigational system. Third generation avionic architectures share a common digital interconnect infrastructure. Elements of a separate aircraft system, such as the communications system, also share a common digital databus, separate from the databus supporting the navigation system.
Fourth generation avionic architectures evolved in response to advances in digital signal processing technologies. As the electronics used to switch digital signals progressed, it became feasible to process signals from multiple distinct aircraft systems within a single high-throughput switch. Digital signals from the navigation system, as well as signals from communications and other systems, are brought to a central facility for processing and distribution. The centralized processing and switching that defines fourth generation avionic architectures create opportunities for the integration of information that were previously unattainable.
In military aircraft, for instance, information from multiple systems may be integrated by way of the central facility to support a pilot during a mission. For example, the central facility may integrate information from radar systems, indicating, for example, presence of an aircraft with a specific threat signature (e.g., friend or foe), with a digital map of the terrain and mission profile, to create a comprehensive situational awareness for the pilot. Other information pertinent to the mission, such as the location and activities of other mission participants, could be integrated within the same situational awareness.
Other opportunities borne out of adoption of the central facility included wholesale changes to development, and in turn, manufacturing of processing equipments. For example, most, if not all, of the processing equipments have identical or substantially identical modular hardware elements. Initially, the modular hardware elements are not configured for any specific processing functions. The specific processing functions implemented are determined through software design and application of the software design to the modular hardware elements. In effect, what previously had been a dedicated hardware element with associated dedicated software, has evolved into multi-functional hardware elements with dedicated software. By developing software for a known, common hardware platform, development time and cost were reduced substantially, and upgrading system capabilities became a software development task.
In advanced tactical fighter aircraft, such as the E2-D, F/A-18 and F-35, integrated switching is provided by core switches and switching. In other advanced aircraft, integrated switching is provided by core switches and switching fabrics that are based upon the Ethernet standard promulgated by the Institute for Electrical and Electronics Engineers (“IEEE”) under IEEE 802.3; derivatives of the Ethernet protocol, such as Aircraft Full Duplex (“AFDX”); or Aeronautical Radio, Incorporated (“ARINC”) standard 644P7 (“ARINC 664P7”). In these tactical aircraft, digital signals from the navigation, communications, radar, electronic warfare and electro-optic systems are brought to the core switch, which routes and forwards the digital signals to their destinations for subsequent processing. Switched signals are carried in electronic format using electrical wiring or in optical format using optical fiber.
The above generations of avionics architecture may not be sufficient for the data capacity requirements in that, for example, anticipated data capacity requirements may overwhelm the capabilities of core switches. Specifically, projections for aggregated data throughput on typical tactical or transport aircraft are expected to exceed 1 Tb/s in the near future. At the same time, a single optical fiber has the capacity to carry more than 10 Tb/s (10,000 Gb/s) of information. This may exceed the switching capacity a core switch fabric on an aircraft. The resulting disparity between switching requirements and the capabilities of an electronic core switch fabric indicate a need for a high capacity switching technology that is compatible with operation on aircraft platforms.
Thus, there is a need for supporting legacy aircraft, having distributed or unified avionics architectures, as well as the need to support the next generation aircrafts, to anticipate the new generation data capacity requirements.